Assessment of Cochlear Dysfunction in Black and White Adults with Stage 2 Hypertension Using High-Frequency Distortion Product Otoacoustic Emissions - Little is known about the relationship between hypertension (HTN) and auditory dysfunction in the Black adult population and to what extent it differs from that in White persons. Experimental work shows the cochlea is irreversibly damaged in HTN, making early identification of cochlear dysfunction in persons with this modifiable condition critical to reducing the disease burden of age-related hearing loss (ARHL). It is also known that HTN disproportionately affects Black persons. The long-term goal of this line of research is to reduce the public health burden of ARHL by devising clinical efforts for early identification and intervention of persons with modifiable determinants of acquired hearing loss. The overall objective of this application is to assess cochlear function in Stage 2 HTN (a severe elevation in blood pressure) and characterize differences in this relationship between Black and White adults. The central hypothesis, supported by past studies and the applicant’s preliminary data, is that, compared to normotensives, outer hair cell health is compromised in persons with Stage 2 HTN and that White adults experience greater compromise than Black adults. The rationale for this work is that once the extent of auditory damage in Stage 2 HTN is determined, clinical protocols for early evaluation of auditory vulnerability in persons with HTN can be established, which will support earlier intervention. The central hypothesis will be tested by pursuing two specific aims: (1) assess functional integrity of the cochlea in persons with Stage 2 HTN and (2) characterize Black-White differences in the association between Stage 2 HTN and cochlear dysfunction. Adults aged 18-85 years with normal blood pressure (controls) or Stage 2 HTN will undergo extensive behavioral and swept-tone distortion product otoacoustic emission (DPOAE) testing. Under Aim 1, swept-tone DPOAEs will be collected from f2 of 1-20 kHz. Under Aim 2, linear mixed effects modeling will disentangle the effects of HTN, race, sex, and potential confounders on auditory function with a focus on cochlear health. Innovation aspects of this research include the methodological approach (swept-tone high-frequency DPOAEs), statistical modeling (which will disambiguate the effects of HTN from other contributors to ARHL), and assessment of racial differences. The proposed research is significant because it is a vital step in devising clinical efforts for early identification and intervention of persons with modifiable determinants of acquired hearing loss and will provide critically needed data on cochlear dysfunction in Black adults, a historically under-studied population. Capturing auditory dysfunction early in the disease process is important because hearing loss, even in the subclinical stage, is associated with negative outcomes. Ultimately, knowledge gained from this research will inform development of clinical tools and protocols to improve early identification of auditory dysfunction in persons with medical comorbidities such as Stage 2 HTN with the end goal of advancing more effective therapeutic solutions.
